1. Field of the Invention
The present invention relates generally to the provision of downlink packet access services to a mobile station in a spread spectrum communication network. The invention is suitable for use in the provision of such services to a user equipment in a communication network conforming to the 3GPP-LTE standards being developed by the 3rd Generation Partnership Project (3GPP), and it will be convenient to describe the invention in relation to this exemplary, but non-limiting, application.
2. Description of the Related Art
Recent enhancements in packet transmissions such as High Speed Downlink Packet Access (HSDPA) and enhanced uplink technology have made 3GPP radio-access technology highly competitive. In order to ensure that the competitiveness of this technology continues over a long time frame, a long term evolution of 3GPP radio-access technology is being developed. This new technology is known as Super 3G.
Important parts of the long term evolution of Super 3G technology will include Radio Access Network (RAN) latency reduction, higher user data rates, improving system capability and coverage, and reducing cost to a network operator. In order to achieve this, an evolution of the radio interface as well as the radio network architecture is being considered. The objective of this evolution is to develop a framework to enable high data rate, low-latency and packet-optimized radio-access.
Development of the Super 3G system has been focused on supporting services provided by the PS-domain, such as enhanced HSDPA, Multimedia Broadcast Multicast Services (MBMS), High Speed Uplink Packet Access (HSUPA) and other similar types of packet-switched services including Voice Over IP.
Existing HSDPA services in Wideband Code Division Multiple Access (WCDMA) systems are currently provided in a manner that is dependent on other dedicated RAN services. This results in an extremely complicated protocol stack design, and hinders the development of HSDPA services in WCDMA.
The Super 3G system will be developed to support enhanced HSDPA and other types of packet-switched services. However, reusing the existing HSDPA-related procedures that have been developed for the WCDMA system will lead to a situation where the future 3G system shall be coupled with and operationally dependent on existing WCDMA technology. This interdependence is likely to result in an even more complicated RAN architecture, which will then increase the cost of design, manufacture and operation of the Super 3G system.
There therefore exists a need to enable enhanced HSDPA services to be introduced into the future Super 3G system in such a manner as to be able to operate independently from the existing 3G-WCDMA system when considered from the RAN perspective. There also exists a need to provide enhanced HSDPA services in a manner that ameliorates or overcomes HSDPA service provision techniques.